Electro-magnetic coordinate switch



Sept. 5, 1961 c. R. J. DUMOUSSEAU ET AL 2, 4

ELECTROMAGNETIC COORDINATE SWITCH Filed Nov. 12, 1958 2 Sheets-Sheet 1 At F|G.l 4Z1".

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ELECTROMAGNETIC COORDINATE SWITCH Filed Nov. 12, 1958 2 Sheets-Sheet 2 Inventors Attorney 2,999,140 ELECTRO-MAGNETIC COORDINATE SWITCH Giaude Ren Jean Dumousseau, Neuilly-sur seine, and

Emile Touraton, Paris, France, assignors to international Standard Electric Corporation, New York, NIL,

a corporation of Delaware Filed Nov.12, 1958, Ser. No. 773,441 tllaims priority, application France Dec. 3, 1957 5 Claims. (Cl. 200-104) This invention relates to electromagnetic coordinate switches, and more particularly to the type of switch in which the magnetic fields, used to control selectively the closing of .an electric contact, act directly on the contact elements. It concerns in particular coordinate switches using sealed contacts, known usually in the art under the name of reed relay.

The directly actuated contacts known as reed contacts which are commercially available, are made up of two blades made of magnetic material, arranged inside a sealed glass tube and which may contain an inert gas. The two blades are arranged in such a way that their free ends overlap but are spaced slightly apart from each other. When one contact of such type is placed in a magnetic field of suitable intensity, the two blades come into contact. The :free ends of the blades may be provided with precious metal contacts, as it is well known in the contactor or the electromagnetic relay technique. A description of this type of device will be found in the .French Patent No. 852,275. A contact in which the control magnetic field acts directly upon the blades without requiring the intervention of moving magnetic armatures, as is the case in the usual elec tromagnetic relays used in the automatic telephony technique, is thus available. In the continuation of the description, such a contact is designated under the name of elementary contact.

it has already been proposed especially in the US. Patent 2,187,1l5, to build up coordinate switches with n inputs and p outputs, using such elementary contacts. However, in the proposed device, the holding in operating position of the elementary contacts previously actuated is obtained by'energizing the control coils with a fraction of the control current.

Accordingly, one of the objects of the present invention is the provision of a coordinate switch which per mits selective connections between 11 inputs and p outputs, and is of simple construction, especially from the point of view of the magnetic circuits used for the control of the elementary contacts.

The above-mentioned and other features and objects of the invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following descri tion of an embodiment of the invention taken in conjunction with the accompanying drawings in which:

FIG. 1 is a graph showing the operating characteristics of a known type of relay;

FIG. 2 is a front elevation partly in section of a reed relay coordinate switch arrangement according to the invention; and

FIG. 3 is a plan view partly in section of the multiconnected reed relay arrangement according to the invention.

Referring now to FIG. 1, there is shown a graph of the operating characteristics of a known type of reed relay and whose ordinate is calibrated in ampere turns. The graph shows curves of sample relays which have been tested and in which the margin of operation occurs between the range of 47.5 and 75 ampere turns. Once actuated, the number of ampere turns may be decreased and as long as the magnetomotive force is not decreased nited States Patent below the value which would be developed by 20 ampere turns the relay will remain actuated. Thus, it will be seen that the maintaining force is considerably less than the operating force.

Referring now to FIGS. 2 and 3, there is shown one embodiment of our invention which consists of a coordinate switch comprising individual reed relays arranged in rows of ten each and actuated by common magnetic means, which will be later described in detail. It should be understood that more or fewer than 100 individual reed relays may be utilized without departing from the scope of our invention.

FIG. 2 is a front elevation, partly in section, of a coordinate switch device and which consists of a rectangular frame 1 made of magnetic material. In addition to supporting the elements making up the device, the frame acts as a magnetic shield for the whole assembly. The individual reed relays which comprise an envelope, such as C10, in FIG. 3, are made of non-magnetic material through whose opposite ends a pair of contact blades 3, 4 are positioned. The free ends of the blades 3, 4 overlap but are spaced from each other a predetermined distance. The overlapping portions may be provided with suitable contact material, such as a rare metal. In addition each envelope may be filled with an inert gas under suitable pressure and which gas will inhibit arcing of the contacts. Each blade 4 is brought out at one end of its envelope and is mounted on a magnetic bar, such as N10, which extends transversely across the row of envelopes, shown in FIG. 3. It should be understood that there is a separate bar N11 N19 for the other rows of envelopes shown in FIG. 2.

The upper blades 3 are similarly mounted to bars N1 N9, as shown in FIG. 3. It will be seen that the bars N1 N9 are normal to the bars N10 N19. Each of the bars N10, N11, etc., cooperate with their individual windings B10, B11, etc., and these windings are shown to be staggered in FIG. 2, so that the bars may be nested more closely together. The several bars extend through opposite sides of the frame .1 through magnetic joints 6. The frame 1 thus acts as a magnetic yoke for the several bars N1 N19.

As will be seen from FIG. 2, there is a first common winding 11 extending over all of the horizontal bars N10 N19 adjacent one end thereof, and there is a corresponding common winding 12 extending over the opposite ends of the same bars and their respective energizing windings. There are similar pairs of common windings 13 and 14 extending over the windings Bi B9 and the corresponding windings at the other end of the bars N1 N9, respectively. In FIG. 2 the common coils 11 and 13 are shown in section.

At each coordinate point defined between the two groups of bars, there is placed a contact pair Within its individual envelope. The design of the coiis 11 14 is such that when energized they exert a magnetomotive force equivalent to 20 ampere turns and which force is insufficient to actuate any of the contact pairs. The individual coil pairs, such as B0 and B10, are designed so that they will develop a magnetomotive force equivalent to 27.5 ampere turns. Thus, when the individual coils are energized in the same direction electrically as the common coils, the total magnetomotive force generated will be the equivalent of 47.5 ampere turns and sufiicient to operate a coordinate pair of contacts, as shown in the graph in FIG. 1. When potential is removed from the operating coils, the common coils are maintained energized and the 20 ampere turn magnetomotive force is exerted on the operated contact pair.

In order to cause the operated contacts to open, it is necessary to apply a current to the control windings of opposite polarity to that applied to the common windings. This will cause a magnetomotive force equivalent to 27.5 ampere turns in the opposite direction to the magnetoniotive force of 20 ampere turns furnished by the common windings and the operated contacts will open.

The several bars in both groups of horizontal and vertical bars may be electrically insulated from the frame 1 by any suitable means. One such means would include a ferrite bushing (not shown) surrounding each bar at the opening 6 in the frame '1. Alternatively, a ferrite bushing may be inserted in each of the bars at coordinate points so that the terminal ends of the contacts 3, 4:, may pass therethrough and separate electrical leads may be attached thereto. This gives an added advantage in that more than one pair of contacts in a row may remain actuated while the electrical circuits controlled thereby are mutually isolated. This embodiment is not illustrated, but it will be apparent to those skilled in the art as to how this may be accomplished. The embodiment shown in the rawing uses the several bars in each group as electrical conductors.

It may be necessary to increase the iron gap between each contact blade and the magnetic core to which it is associated so that the magnetic circuit will not be affected by the reluctance variations of the holding circuit produced by the closing of varying numbers of contact pairs.

It will be seen that a simple crossbar switch is achieved by this invention.

While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention, as set forth in the objects thereof and in the accompanying claims.

What is claimed is: 1.1 An electromagnetic coordinate switch comprising ,a switch frame, a group of spaced horizontal magnetic a separate one of said contact sets at each coordinate point of said horizontal and vertical bars and in fluxtransfer relation therewith, the selective energization of the said individual coil means associated with any horizontal and any vertical bar causing the generated flux to traverse the associated bars and operate the contact set located at the coordinate points thereof, and the energization of the said common flux, generating coil means associated with each group of horizontal and vertical bars causing the flux generated thereby to traverse all of said horizontal and vertical bars to maintain the operated contact set in operated condition after the said individual coil means are de-energized.

2. An electromagnetic coordinate switch according to claim 1 wherein the saidcontact sets supported at the coordinate points of the horizontal and vertical bars are electrically insulated therefrom.

3. An electromagnetic coordinate switch as claimed in claim 1, wherein said individual coil means when energized by a suitable current flowing in a direction opposite to the direction of a current flowing in said common coil means develop a suflicient magnetomotive force to counter the magnetomotive force exerted by said common coil means on an operated contact set to cause the release of such set.

4. An electromagnetic coordinate switch as claimed in claim 1, wherein said individual coil means comprises a pair of windings disposed on opposite portions of said bars adjacent opposite sides of said frame, respectively.

5. An electromagnetic coordinate switch as claimed in claim 4, wherein said common coil means comprises a pair of windings disposed on opposite portions of the bars of said groups, respectively, and adjacent opposite sides of said frame, each of said common coil windings extending over the individual coil windings adjacent the same side of said frame as said common coil winding.

References Cited in the file of this patent UNITED STATES PATENTS 2,187,115 Ellwood et al. Jan. 18, 1940 2,397,123 Brown Mar. 26, 1946 2,535,400 Ellwood Dec. 26, 1950 2,630,506 Buch Mar. 3, 1953 2,821,597 Germanton et al Jan. 28, 1958 2,836,676 Wirth May 27, 1958 2,902,558 Peek Sept. 1, 1959 

